Biomedical subjects
Publications and source records attributed to D R Hardten.
As we stand at the threshold of a new millennium, perhaps nowhere else in the field of ophthalmology is there such a feeling of excitement, enthusiasm, and anticipation as in the subspecialty of refractive surgery. What was once considered an experimental hobby, dabbled in by a few rogue physicians, has now gained a level of respect among patients and ophthalmologists that has surprised even its most vocal critics.
PURPOSE: To assess the safety and efficacy of laser in situ keratomileusis (LASIK) for secondary hyperopia and hyperopic astigmatism and to develop a VISX STAR S2 LASIK nomogram (VISX Inc., Santa Clara, CA) for consecutive hyperopia after prior myopic refractive surgery. DESIGN: Prospective, nonrandomized, self-controlled interventional study. PARTICIPANTS: Thirty patients with consecutive hyperopia or hyperopia and astigmatism after LASIK, photorefractive keratectomy, automated lamellar keratoplasty, or radial keratotomy. INTERVENTION/METHODS: Prospective evaluation of LASIK in 30 secondary eyes with fogged manifest sphere from +0.5 to +6.0 diopters (D) and cylinder from 0 to +5.0 D. MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), and spherical equivalent (SE). RESULTS: Mean manifest SE was +1.73 +/- 0.79 D before surgery, -0.13 +/- 1.00 D at 6 months after surgery, and -0.18 +/- 1.08 D at 1 year after surgery. At 6 months, 84% of patients with secondary hyperopia had UCVA of 20/40 or better; 76% were within +/-1 D of emmetropia. At 1 year, 85% had UCVA of 20/40 or better and 85% were within +/-1 D of emmetropia. No patients with secondary hyperopia lost 2 or more lines of BCVA at 1 year. Complications included intraoperative bleeding (3.3%), intraoperative epithelial defect (3.3%), transient interface debris (3.3%), significant dry eye (3.3%), blood in interface (3.3%), irregular astigmatism (6.7%), slight decentration (6.7%), trace haze (6.7%), or mild epithelial ingrowth not requiring removal (3.3%). CONCLUSIONS: These early data suggest that LASIK for consecutive hyperopia from +0.5 to +5.50 D and astigmatism from 0 to +2.75 D using the VISX STAR S2 benefits from a nomogram adjusted for preoperative refraction, age, and prior refractive surgery, and is safe and effective.
With the volume of laser in situ keratomileusis procedures growing exponentially, ophthalmologists and other eye-care providers are becoming aware of an uncommon postoperative condition, diffuse lamellar keratitis, that can affect an otherwise ideal outcome. We present our strategy for diagnosing and managing this syndrome, developed from experience in a high-volume refractive surgical practice. Understanding the time course of the disease, along with proper identification, staging, and intervention, can help eliminate visual loss associated with this condition.
PURPOSE: To examine the results of laser in situ keratomileusis (LASIK) after removal of intracorneal ring (ICR) segments. SETTING: Active refractive surgery practice. METHODS: The effect of ICR (0.45 mm) placement, the rapidity of refractive recovery after explantation, and the results of subsequent LASIK were examined in 5 eyes. RESULTS: Four eyes developed induced astigmatism after ICR implantation. In 2 of these eyes, retained astigmatism was evident by manifest refraction or corneal topography even after ICR explantation. In 1 eye, the ICR procedure was aborted because of an intraoperative complication. All 5 eyes had subsequent uneventful LASIK. CONCLUSIONS: Intracorneal rings can induce astigmatism that may be retained even after explantation. Careful wound manipulation may reduce the incidence of this complication. Laser in situ keratomileusis after ICR removal appears to be safe and effective.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The status of the cornea is crucial to a good outcome with cataract extraction. Preexisting corneal disease must be managed appropriately to get the high-quality results that we have come to expect with cataract surgery. It is now more common to perform cataract surgery on patients with previous corneal refractive surgery, and in these patients intraocular-lens power calculation is more challenging. Complications following cataract surgery and intraocular-lens implantation that involve the cornea are uncommon because of advances in surgical techniques. Corneal complications can include mechanical or toxic injury of the endothelium, stripped Descemet's membrane, epithelial toxicity and disruption, infectious keratitis, and epithelial ingrowth. Endothelial-cell survival after cataract extraction and lens implantation is still the major concern. Healing of the cornea following clear corneal incisions has become more important, as this technique is more frequently used. Patients with ocular surface disease still require extra lubrication and management of blepharitis to prevent epithelial toxicity at the time of surgery as well as postoperatively. Clear corneal cataract extraction and lens implantation causes minimal disruption of the conjunctiva, allowing cataract surgery to be performed in patients with severe ocular surface disease such as ocular cicatricial pemphigoid. Overall, modern-day cataract extraction is very safe for the cornea.
PURPOSE: To assess the safety and efficacy of laser in situ keratomileusis (LASIK) for hyperopia and hyperopic astigmatism and develop a LASIK nomogram for primary hyperopia or hyperopia secondary to myopic refractive surgery using the VISX STAR S2. METHODS: Prospective evaluation of LASIK in 46 primary eyes and 29 secondary eyes with fogged manifest sphere from +0.5 diopters (D) to +6.0 D and cylinder from 0 to +5.0 D. RESULTS: Mean manifest spherical equivalent (SE) in patients with primary hyperopia was +2.50 D +/- 0.93 preoperatively and +0.70 D +/- 1.19 at 6 months. At 6 months, 79% of primary hyperopes had uncorrected visual acuity (UCVA) of 20/40 or better; 63% were within +/- 1 D of emmetropia. One primary hyperope lost 2 lines of best spectacle-corrected vision (BCVA) at 1 month. Complications included transient epithelial defect (6.5%), epithelial cells in the interface (4.3%), diffuse lamellar keratitis (4.3%), haze (2.2%), and mild irregular astigmatism (2.2%). In those with secondary hyperopia, mean manifest SE was +1.70 D +/- 0.82 preoperatively and -0.27 D +/- 0.95 at 6 months. At 6 months, 83% of secondary hyperopes had UCVA of 20/40 or better; 74% were within +/- 1 D of emmetropia. No secondary hyperope lost > or = 2 lines of BCVA. Complications included intraoperative bleeding (3.4%), intraoperative epithelial defect (3.4%), transient interface debris (3.4%), significant dry eye (3.4%), blood in interface (3.4%), irregular astigmatism (6.9%), slight decentration (6.9%), trace haze (6.9%), mild epithelial ingrowth not requiring removal (3.4%), or corneal irregularity (3.4%). CONCLUSION: These early data suggest that LASIK for hyperopia from +0.5 to +6 D and astigmatism from 0 to +5 D using the VISX STAR S2 benefits from a nomogram adjusted for preoperative refraction, age, and prior refractive surgery and is safe and effective. Patients with secondary hyperopia achieved more correction than those with primary hyperopia, although the accuracy and predictability of LASIK in both groups has improved with the nomogram adjustments.
PURPOSE: To evaluate the visual outcomes in patients having photorefractive keratectomy (PRK) to correct residual myopia after radial keratotomy (RK). SETTING: Nine refractive surgery centers in the United States and one in South Korea. METHODS: This retrospective analysis comprised 38 eyes of 32 patients treated with PRK after RK and followed for 12 months. Analysis was based on pre-RK and pre-PRK refraction as well as response to RK (pre-RK minus pre-PRK refractions). RESULTS: Mean pre-RK and pre-PRK refractions were -8.11 diopters (D) +/- 2.92 (SD) and -4.28 +/- 2.08 D, respectively. One month after PRK, mean refraction was +0.42 +/- 1.56 D and regressed to -0.95 +/- 1.24 D at 12 months. At 12 months, 65% of eyes had an uncorrected visual acuity of 20/40 or worse, and 11.1% lost 2 or more lines of best corrected acuity. Of eyes with an original erro of -6.00 or less, 81.8% were within +/- 1.00 D of intended correction at 12 months and of those with an original error of -9.12 to -20.00 D 50.0% (P = .004). All eyes with residual (pre-PRK) errors of -3.00 D or less and 42.9% with a residual error of -6.12 to -9.00 D were within +/- 1.00 D of intended correction (P = .07). There were no statistically significant differences in the response to PRK between eyes that had an RK response of 0 to 3.00, 3.12 to 6.00, or 6.12 to 12.00 D. CONCLUSION: Patients with lower original and residual myopia achieved better visual outcomes after PRK than those with higher myopia. The amount of myopic correction achieved using RK was not predictive of the amount of myopic correction using PRK.
The status of the cornea is crucial to a good outcome with cataract extraction. Preexisting corneal disease must be managed appropriately to get the high quality results that we have come to expect with modern day cataract surgery. It is now more common to perform cataract surgery on patients who have had previous corneal refractive surgery, and in these patients intraocular lens power calculation is more challenging. Complications following cataract surgery and lens implantation that involve the cornea are uncommon because of advances in surgical techniques. Corneal complications can include mechanical or toxic injury of the endothelium, stripped Descemet's membrane, epithelial toxicity and disruption, infectious keratitis, or epithelial ingrowth. Endothelial cell survival after cataract extraction and lens implantation is still the major concern. Healing of the cornea following clear corneal incisions has become more important, as this technique is used more frequently. There are several recent studies looking at the results of clear corneal incisions performed for cataract surgery. Patients with ocular surface disease still require extra lubrication and management of blepharitis to prevent epithelial toxicity at the time of surgery as well as postoperatively. Clear corneal cataract extraction and lens implantation cause minimal disruption of the conjunctiva, allowing cataract surgery to be performed in patients with severe ocular surface disease such as ocular cicatricial pemphigoid. Overall, modern day cataract extraction is very safe for the cornea.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Corneal complications following cataract surgery and intraocular lens implantation continue to be more unusual because of advances in our surgical techniques. Complications can still occur, however, and can include mechanical or toxic injury of the endothelium, stripped Descemet's membrane, epithelial toxicity and disruption, infectious keratitis, and epithelial ingrowth. Endothelial cell survival after cataract extraction and lens implantation are still major concerns. Healing of the cornea following clear corneal incisions has become more important as this technique is more frequently used, and several studies are looking at the results of clear corneal incisions performed for cataract surgery. Patients with ocular surface disease still require extra lubrication and management of blepharitis to prevent epithelial toxicity at the time of surgery as well as postoperatively. As incisions move back to the cornea from the distant limbus, careful observation for complications involving the cornea will be needed. Still, modern day cataract extraction and lens implantation are extremely gentle on the cornea.
PURPOSE: To evaluate the efficacy, safety and predictability of LASIK in the treatment of low, moderate and high myopia. METHODS: A perspective study of LASIK for low myopia of -0.75 to -6.00 with less than +1 D of astigmatism and for moderate and high myopia of -6.12 to -20 D with astigmatism up to +4.50 D was performed at our institution from March through November, 1996. The Chiron automated corneal shaper was used for the initial flap, and either the Summit or VISX laser was used for the refractive ablation. Preoperative refraction, uncorrected and corrected visual acuity were compared to postoperative refraction, uncorrected and corrected visual acuity. One day and 1 month results were available on all patients. RESULTS: In the low myopia group 101 eyes underwent LASIK with a mean preoperative spherical equivalent of -4.16 +/- 1.41 D (-0.75 D to -6.00 D). Mean preoperative astigmatism was +0.4 +/- 1.29 D (0 to 0.75 D). At 1 day, 48% were 20/25 or better and 80% were 20/40 or better. The day 1 mean spherical equivalent was +0.4 +/- 0.75 D with 86% between +/- 1.00 D of emmetropia. At 1 month, 50% were 20/25 or better and 90% were 20/40 or better. The 1 month mean spherical equivalent was -0.26 +/- 0.65 D with 89% between +/- 1.00 D of emmetropia. In the high myopia group 198 eyes underwent LASIK with a preoperative mean spherical equivalent of -8.34 +/- 2.15 D)-6 to -20D) and a mean preoperative astigmatism of +1.18 +/- 0.88 D (0 to +4.5 D). At 1 day postoperatively, 17% were 20/25 or better, and 61% were 20/40 or better. The mean day one spherical equivalent was -0.26 +/- 1.56 D with 58% between +/- 1.00 D of emmetropia. At 1 month, 35% were 20/25 or better and 71% were 20/40 or better. The 1 month mean spherical equivalent was -0.28 +/- 1.18 with 63% within +/- 1.00 D of emmetropia. CONCLUSION: Early results of using LASIK to treat low, moderate and high degrees of myopia with and without astigmatism appear promising, although longer follow-up and nomogram refinement are needed.